SPID#: 32 The principal objectives of this work with female chimpanzees (Pan) were to [A] Non-invasively monitor circulating estrogens and progesterone using an external marker (the Perineal Sex Swelling, PSS) to either enable synchronization of Artificial Insemination (AI) procedures or identify abnormal conditions that reduce fertility, cause puerperal pathologies, or indicate luteal phase and pre-menstrual pathologies; [B] Test hypotheses about the way that nipple stimulation behavior (NSB) disrupts the progress of the ovarian cycle, implantation, and the establishment of pregnancy; [C] Evaluate the role of stress as either a part of the auto-NSB phenomena or as an independent contribution to infertility. Hyperprolactinemia in adult female Pan caused by NSB is found to prolong the duration of post-partum amenorrhea. It has also been documented at this laboratory that NSB in many mothers continues after ovarian cycles have resumed but that the cycles have an aberrant and non-fertile pattern of ovarian activity. It is hypothesized that the au-NSB causes a disruptive mechanism that prevents conception and implantation probably through the action of prolactin and/or oxytocin. Stress associated with AI or au-NSB may be a confounding or associated disruptive influence. Efforts to understand these mechanisms continued with foci on irregular ovarian cyclicity, measurements of circulating prolactin, urinary cortisol, and behavior. During this reporting period; [1] Daily scores of the PSS were made on an average of 60 females yielding a total of 22,000 data points (total data set now about 125,000 data points); [2] An additional 250 hours of behavioral data on both allo- and auto-NSB (al-NSB and au-NSB) were collected from 8 subjects (total data set now 1,150 hours on 28 subjects). Moreover, for 150 tests on five subjects (two without and three with infants) all self-directed behaviors (SDBs) were quantitatively assessed (in addition to au-NSB and al-NSB) so that variation in NSB could be contrasted with all other SDBs in the way that they varied with environmental conditions (subject inside or outside, disturbance), physiological state (amenorrhea and lactation, swelling phases of the ovarian cycle and associated estrogen and progesterone fluctuations, circulating PRL), parity, number of months post-partum or age of the infant and weaning, and activity level. SDBs were found to vary with parity, with location, and with activity level but did not vary significantly with phases of the cycle as did au-NSB. SDBs were significantly reduced after resumption of ovarian cyclicity, however, whereas measures of al-NSB increased approximately 3-5 fold when mothers (with infants) resumed ovarian cycles. These data suggest that au-NSB by mothers without infants during luteal phases more closely resemble al-NSB during weaning when ovarian activity resumes than they do al-NSB during lactational amenorrhea. Study foci during 1996 will include the analyses of stockpiled-blood and urine samples for prolactin and cortisol, further analyses of swelling data and evaluations of abnormality, and more behavioral observations to increase the numbers of subjects in a number of categories Mothers with young infants, with weaning infants, with weaned juveniles; subjects without infants with or without au-NSB. A new method will be applied for indexing urinary "free" cortisol (uF). This method was developed in this laboratory through knowledge that free cortisol is not actively transported across the kidney. Application of this method allows recognition of baseline uF (reflecting inactivation of the HPA), high uF (reflecting major HPA activity), and uF increased over baseline suggesting chronic low HPA activity. In general, this work continues to accumulate evidence for the important role of the chimpanzee female as a model for understanding stress related pathologies in the woman.